The very first virus might have been
nVir of 1987
Although technically not one, nVir worked much like a boot sector virus. Its source code did circulate on BBSes very soon after, leading to short flooding of copies. Still the damage was rather small. Not much later
HyperAvenger of 1988 (also called Dukakis-Virus)
made its debut. It was based on HyperCard ...
They were most likely wrinkled like that from the start, due to the way they were manufactured, and thus you should not be worried.
Until the mid-90s, boards often went through an HASL, or "hot air solder leveling" process that put solder on the traces before the solder mask (a protective layer over the board) was applied. This initial solder over the PCB's ...
Why Mac systems were always faster than Windows in processing performance?
Mind to give any proof to this claim?
According to various Benchmarks, the PCs usually outperform Macs of the same time.
For example a classic Macintosh (68k @ 7.8 MHz; *1) delivered about 0.40-0.52 Dhrystone MIPS (*2), while a PC/AT (80286 @ 6 MHz) scored 0.40 to 0.71 DMIPS - that'...
Yes, part of the POST sequence (which occurs before the display lights up) is a simple memory test which also serves to detect how much RAM is present. The Mac then sets up the hardware and its internal variables to reflect the actual RAM configuration.
Attempted accesses of addresses which do not map to memory will either see a dead bus or alias to ...
That is a vague description. But the Enterprise (saucer section?) and massive guns in front do ring a bell:
Side-scroller; fly a spaceship on bombing raids over enemy territory, dodging and/or shooting enemy ships and collecting power-ups; land (carefully) on your own turf; repeat. Graphics and sound quite good, but silly. The most fun, when you can manage ...
(I was waiting Raffzahn to write an authoritative answer, but he hasn't yet, so I will write it myself.)
Unless noted, sources are the Guide to Macintosh Family Hardware, 2nd edition, 1990.
680x0 processors expect the reset and exception vectors to reside in low memory (addresses 0x000000 to 0x0003ff). During normal operation, all Macs mapped ...
This could be due to Mac OS having performance optiminizations to run
on Mac hardware?
Artificial benchmarks aside, in real-world applications Macs were generally faster than Windows because the OS was indeed 'optimized' to run on Mac hardware - or more correctly, the hardware was optimized to run a Graphic User Interface. In comparison, Windows had to ...
I’m refurbishing my middle school computer, a Macintosh Performa 635CD
Cool. Eventually one the best 68k machine of all.
Will it hurt the chip?
If applied correctly not. Any increased cooling is welcome. Keep in mind that any heat spreader is at first an additional insulation, so its relative dissapation has to be higher than that.
It it is always a ...
No, it won't hurt it. It's ceramic and you can stick a heatsink on it and it'll work. It might discolour it a little.
The advice you've received is correct. Thermal paste is usually electrically conductive, and it can cause short circuits and potentially cause damage that way, if it leaks over the edge. Given that you don't need a heatsink in the first ...
15.667 Mhz is about 2% less than 16 Mhz. So for purposes of "multiple of max. MC68000 frequency", it is close enough. The Mac wasn't competing based on being the fastest machine, so 2% was just not a big deal. And most of the competition was either older 8-bit or Intel family, not MC68000. In fact, the 8088 in the original IBM PC was clocked at 4.77 Mhz, ...
I fixed it.
I used a known working logic board from a different mac and a multimeter set to continuity to find the bad trace.
first I tested the first 16 pins of the simm slot to the ground on the scsi port on the working board for reference resistances.
Then I compared them on the bad board, I found that pin number 9 was open when it should have matched ...
The first viruses for Mac were targeting Hypercard. The first Hypercard virus appeared in about 1991. Hypercard has a scripting language called HyperTalk, which was powerful enough to perform file-system accesses, thus allowing Hypercard viruses to discover and spread to other stacks (HyperCard "documents").
This is actually a comment, but images cannot be inserted in a comment, so I wrote an "answer", just to point out that this kind of trace looking is already known in other computers, like the ZX Spectrum. AFAIK, this is due to the wave soldering process used.
This is how it looks like on the solder side:
No, not really, the Mac's refresh rate is 60.14 Hz.
I'm missing the exact data on the Lisa, but it's as well close to (or at) 60 Hz (*1).
The Mac timing is a bit odd and built around the Video timing.
Base clock is 7.83 MHz (*2)
Line frequency is 22.255 kHz.
Thus a video line is exactly 352 clock cycles
A 68k needs 4 cycles per read/write
Although the "computer speed" is totally subjective and all those ***stones are just synthetic tests, let's take this question seriously, but from a different point of view.
There are differences between the Intel x86 and the Motorola 68x family. Motorola has a slightly better performance and can do a few more memory operations than an Intel on the same ...
If you'll forgive the imposition, I've been on a benchmark hunt. These tend to skew later because they assume some sort of convergence of application support. Of course, in sticking with a CPU benchmark I'm assuming that the interesting case is application software that does a lot of processing.
On the early days of the 68000 versus the 286, I found both ...
I wrote an emulator earlier the year, so I can answer on the Macintosh.
The processor's clock rate is 7,833,600 Hz; the video subsystem is completely synchronous and completes each line in 352 processor cycles, outputting a total of 370 lines per frame.
Therefore each frame is 130,240 cycles long.
So the original Macintosh produces a touch less than 60.15 ...
(For this Answer I assume your question is about LocalTalk interfaces, not AppleTalk as system)
TL;DR: If at all, the network side could be described as EIA-485.
I guess a basic problem is that not only all of these do have similarities, but LocalTalk in fact uses two different interfaces. One between computer and the little box, and the other between ...
RAM test was common (even ZX48K had it)... How it works:
it simply loop through "whole" address space and detects address mirroring and memory bugs.
// set system limit
// clear memory to zero
for (adr = 0 ; adr <= max_adr ; adr++) mem[adr] = 0;
// test memory is zero and set it to 0xAA
for (adr = 0 ; adr <= max_adr ; ...
The window shown on the screen shot is not MacsBug, but some badly documented, most likely ROM resident debugging facility popping up when MacsBug is not installed. @BrianH mentions correctly to get out of that window with G and Return, though.
Without any other information, my first likely response has to be for you to verify the reassembly. Since I don't know what you actually took apart/disconnected, any errors made putting it back the way it started need to be eliminated first.
If I assume that you did a minimal disassembly of the internals, or have verified everything is back in its proper ...
The users' perception of "processing performance" on Macs vs. Windows PCs is likely influenced by 3 unmentioned differentiators:
The relative performance of all versions of MacOS (macOS) vs. all the contemporary versions of Windows OS.
The particular applications that the users are actually running.
The extent to which the rest of the system has been ...
Are we comparing oranges to oranges?
A difference in the amount of RAM could explain the performance difference.
I recall years ago learning a story that would help explain this.
Macs typically had more memory than their PC counterparts in many colleges(/universities).
Many colleges figured out that PCs were cheaper than Macs. And so they gravitated ...
The PRAM battery for a Titanium Powerbook G4 is rechargeable, it might
not need replacing (though will certainly go flat on the shelf).
The cells are rechargeable lithium/vanadium pentoxide 3V coin cells, similar to
Panasonic VL2020, in a plastic (tape?) wrap, with pigtail connection.
Hold down command-option-P-R at startup to reinitialize PRAM contents;
Some machines required dip switches or jumpers. Some used memory probes. The Commodore VIC-20 and C64 used a non-destructive memory probe which would read each address, then try storing two distinct values, observe whether they read back, and then rewrite the address with its previously-read value. Other machines would write all of memory with various ...
I would argue it is down to product differentiation, as suggested in this story from the Mac team:
"...Sculley is insisting that we charge $2495 for the Mac instead of $1995"
In other words, they could have sold the Mac (at least the original 6809 ...
The kernel of truth to the myth lies in the Lisa. You could get a Pascal dev environment for the Lisa, or you could run the famous pre-Mac multitasking windowed GUI environment. But at launch you couldn't run the Pascal dev environment in the GUI -- it was essentially a completely separate OS. Disk formats weren't even compatible.
As a result, while you ...